Provided are an insulated composite material for structural reinforcement applications, a structural member reinforced with an insulated composite material, and a method for reinforcing a structural member with an insulated composite material.
Composite reinforcement materials have been used to strengthen existing concrete and masonry structures. These composite reinforcement materials generally include a fiber reinforced polymer composite material, such as a glass or carbon fiber textile that is embedded in a matrix such as binder resin.
The use of composite reinforcement materials has proven to be advantageous, because the composite materials are strong, lightweight, highly durable, non-corrosive, and can be easily installed in areas of limited access. The composite reinforcement materials are also easily conformed around complex or irregular shaped structures. In addition, composite reinforcement materials have a low profile and are easy to conceal, thereby resulting in only minimal changes to the appearance of the existing concrete or masonry structure.
While there are a number of advantages to using composite reinforcement materials, the composite reinforcement materials are generally much more combustible than concrete or masonry and, under the conditions of a fire, decrease the overall strength of the structure. Without being bound to any particular theory, it is believed that these composite reinforcing materials prematurely fail when exposed to elevated temperatures due to the softening of the polymeric binder of the composite materials. Due to this fire exposure risk, building code officials and structural engineers have concerns limiting the use of fiber reinforced polymer strengthening systems in internal building structure applications.
Attempts have been made to insulate fiber reinforced composite materials and to provide a system that is suitable for reinforcing concrete and masonry structural members. For example, intumescent coatings have been proposed to be used as an insulating coating over fiber reinforced composite materials. While these intumescent coatings provide a limited fire resistance, the amount of fire and thermal protection provided by such intumescent coatings alone is not sufficient to address the concerns of building code officials or structural engineers regarding thermal protection of fiber reinforced composite materials. Attempts to use gypsum-based materials or inorganic binders to provide insulation to fiber reinforced composite materials have also been made.
Therefore, a great need still exists in the art for structural reinforcement systems that are cost effective, easy to install, that do not significantly alter the appearance of the structural member being reinforced, and which are highly fire resistant to provide improved structural reinforcement of underlying concrete and masonry structural members during a fire.